Hot water pressure relief valve releasing water

Gary Woodward

The boiler water temp is really set at approx 205 degrees. The water in the hot water heater would not get nearly that hot. The relief valve has a rating of 210 degrees.
We need the boiler temp high because our outside temp sometimes get down to -60 degrees and if the boiler water is lower than that it won't keep the house warm.
Thanks for your input,
Gary

Gary Woodward

Our hot water is heated by circulating the water through a tankless water heater coil in our boiler and we have a hot water tank for storage. The 150 psi pressure valve on our storage tank started to release up to a gallon of water at times. Sometimes several times a day and some days not at all. If we reduce the high boiler water tempature to about 190 degrees the problem stops. We need our boiler tempature to be about 210 degrees for proper operation. The pressure valve has been replaced. What might be causing this

ed wallace

relief valve leaking

its due to the hi temp its only rated for 200 degrees at 150 psi at most why do you need 210 degree water

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Bob Sweet

Gary,

Do you have any gauges on the storage tank to see what the actual temp/pressure is in the tank? Whats controlling the domestic water temp?

Bill Nye_2

Thermal expansion

Cold water expands when heated. You may need a thermal expansion tank on the cold water inlet to your storage tank.

What is the water pressure in the domestic cold water piping? Above 80 psi? you may need a pressure reducing valve. Do you have well water?

Most systems are designed around 180°F. I heat my house with 135° or less for 70% of the heating season. Maybe you could do some things to lower that temp and save some money$?

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Bill Nye_2

Thermal expansion

Cold water expands when heated. You may need a thermal expansion tank on the cold water inlet to your storage tank.

What is the water pressure in the domestic cold water piping? Above 80 psi? you may need a pressure reducing valve. Do you have well water?

Most systems are designed around 180°F. I heat my house with 135° or less for 70% of the heating season. Maybe you could do some things to lower that temp and save some money$?

http://www.amtrol.com/thermxtrol.htm

Look here

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JOHN_103

you did not say if you have well or city water
some cities are replacement water meters have
built in check valves which will not allow for
expansion . if thats the case you will need
a tank made for dhw you you would need to check water pressure and adjust pressure in tank to match

Nick_13

Maybe a new boiler?

Isn't that 210 setting awful close to 212, the magic number for steam(i know it takes like 900+ btus to go from 212 liquid to 212 vapor)? I understand that your saying it gets to -60 but we get close to that, the coldest I've seen it was -54, but that is only for a few days out of the year. the other 360 or so days are warmer. I've only been in the business for a few years, but from what I've heard,(I'm sure not all of it true) is that you size a system for the coldest days. For some reason, the company I work for sets the design temp to maintain 160-180. That is only for those -54 days. like the other gentleman said he runs his a lot lower throughout the year. maybe you should look into a new boiler that can maintain at a lower temp, with somekind of setback control for the warmer days. If that doesn't seem logical, you guys let me know, like i said i'm fairly new just a few years in.

joe mac_2

having same prob.

Installed Weil-Mclain Ultra boiler last fall,2004, with a stainless steel ultra indirect W.H. System ran great with no troubles through heating season, however, since the spring with no calls for heat, the T&P drips after hot water usage. I have a backflow and an expansion tank on the cold water feed. The boiler states indirect W.H. zone should run at 190. The boiler return shows consistantly 190-192, yet my T&P still drips after this firing cycle. HELP!

JOHN_103

joe did you match the pressure in your exp tank to the
street pressure?